Primary kids love cheering on their classmates and friends. K-2 students do not mind being "silly", and the movement of cheering can stimulate blood flow to the brain and just provide a simple way to add some excitement to the classroom.
Instead of just clapping or using round of applause, we like to use "fun" cheers in our class. These cheers include things like "The Lookin' Good Cheer" (where students pretend they are looking in a mirror and slicking back their hair on each side while they say "ooh ahh" - then they point at the person(s) they are cheering for and say "lookin' good"!), "Hip Hip Hooray" (where students put their hands on their hips, and say hip hip while moving their hips from one side to the other, then saying hooray while putting their hands in the air), and "Snap, Crackle, Pop" (where students say snap while snapping their fingers, say crackle while rubbing the palms of their hands together, and say pop while clapping once loudly). There is a whole set of cheers cards at http://www.drjean.org/html/monthly_act/act_2004/06_june/06_2004a.html. There is a link in the 1st paragraph to get the Adobe Acrobat version of the cards. Press that link, print, laminate, and hang up on a ring in your classroom for easy access.
I keep these cards on a hook in my room, and I refer to them often. The kids absolutely LOVE it. I introduce 1 or 2 cheers a week at the beginning of the school year until the students know them all. Once the class knows them all, we rotate and do different cheers each time! Over the years we've made up some of our own cheers, but this list will definitely get you started.
We also use some of these cheers for EPR. When we ask the class a question, we allow the students think time. To show they are ready to share, they have to do whatever cheer we ask for. Then the teacher knows when the students are ready to share with a partner/group/friend/class. We use the above mentioned cheers, but we also use some EPR "movements." For instance, we might say, "when you have thought of your answer, show us by doing chicken wings." Some of the other actions we use in addition to the cheers include: elephant trunk, spider on your head, raise the roof, fist pump, funny nose (thumb on nose while wiggling fingers), mickey mouse ears (open/close fists by ears), sparkle/sparkle fingers, and sign language applause.
These types of activities may seem simple, but the students LOVE them! Enjoy incoporating them into your classroom routine and climate, and they will soon become second nature. =)